Apple appears to have more-or-less officially gone with China Unicom as its exclusive iPhone wireless carrier and according to an article in International Business Times, the carrier has purchased five million WCDMA iPhones without Wi-Fi from Apple at a price of 10 billion yuan (US$1.46 billion).

China Unicom is slated to begin selling the 3G phones in September at company stalls in Carrefour stores, as well as at several large China Unicom retail outlets. The phones are expected to sell for 2,400 yuan (US$352 as of this writing) for an 8GB model and 4,800 yuan (US$704) for a 16GB iPhone. It’s estimated that Apple’s profit from each sale is about 1,100 yuan (US$161).

The carrier currently faces stiff competition from black market iPhones, which are selling for as low as 400 yuan (US$59) and the article notes that Apple made large concessions to China Unicom in order to enter the massive Chinese market. To give some scale to the size of this sale, Apple reported during the 3Q 2009 conference call with Wall Street analysts that they had sold a total of 5.2 million iPhones in the last quarter.

Late Wednesday, Apple released Security Update 2009 – 004 for Mac OS X 10.4 and Mac OS X 10.5. The new update, which can be located and installed via Mac OS X’s Software Update feature, repairs a vulnerability in software package BIND that could let a remote party interrupt the Domain Name System service. According to Macworld, BIND has previously been the target of hackers, most notably a major vulnerability exposed by security expert Dan Kaminsky in 2008 that was later patched by Apple and other software vendors. On the upside, while BIND is included in OS X (both server and client editions) it’s not enabled by default.

If you’ve tried the update and have any feedback to offer, let us know in the comments.